Indicating means for use with plastering



y 7, 1959 H. E- KAUFMAN 2,893,345

INDICATING MEANS FOR USE WITH PLASTERING Filed May 19, 1958 QED MU ll.nll W" Ill NI/E/VTOR:

5 W 4 Mmm ATTORNEYS.

United States Patent INDICATING MEANS FOR USE WITH PLASTERING Harry E.Kaufman, Chicago, Ill.

Application May 19, 1958, Serial No. 736,388

14 Claims. (Cl. 116-114) This invention relates to an improvedconstruction for a service receptacle and more particularly to a devicefor indicating the position of a service receptacle through the plasterof the wall in which the service receptacle is located.

In the construction of buildings and the like, the service receptacles,such as for electric service, are normally positioned within the wallframework, so that after the wall is plastered, the receptacle may bepartially or completely hidden within the wall under the plaster.Frequently, after plastering is completed, and if the receptacle hasbeen covered with plaster, it becomes diflicult to locate the exactposition of the covered receptacle. Since the plaster must be brokenthrough to obtain access to the receptacle, it will be understood thatthe wall is damaged during the search for the receptacles. Of course,the search for lost receptacles is costly, both in search time and inrepair time for replastering erroneously made holes.

Another problem arises in that, normally, the service receptacles areopen on their outer sides, as it is desired to have access to theinterior of the receptacle after the wall has been plastered. It is, ofcourse, undesirable if plaster gets into the receptacle through the openend thereof during the plastering operation, or if plaster gets into thetapped screw-receiving holes that are normally provided on the outermounting face of the recep tacle, as much time and effort is consumed inretapping of plugged holes and in the cleaning out of plaster from suchreceptacles.

In the past, in an attempt to prevent plaster getting into thereceptacle during the plastering operation, the electrical contactor hasresorted to stufiing the recep tacle with waste, such as crumplednewspaper, or the like. However, the use of such an expedient isstrictly a makeshift measure and generally still fails to prevent allplaster from getting into the receptacle, and frequently fails toprevent plugging of the tapped screwreceiving holes.

From the foregoing, it will be appreciated that at present the standardprocedure for the electrician, after plastering has been completed, isto search for the receptacles, clean out the receptacles of wastestufiing and plaster, and re-tap the plugged screw holes in thereceptacles.

One object of the present invention is to provide a position indicatingdevice for use with service receptacles, which will indicate to theelectrician, on the outer surface of the plaster, the exact location ofthe receptacles, thereby avoiding the costly searching for receptaclesthat presently is performed.

Another object of this invention is to provide a novel cover plate forreceptacles which will prevent plaster from entering the receptacle orfrom plugging the screwreceiving holes thereof.

In the practice of this invention, it is contemplated that a receptaclewill be provided with a cover plate which serves a dual function, inthat it covers the open "ice side of the receptacle to prevent plasterfrom getting into the receptacle and into the screw-receiving holesthereof, and at the same time the cover plate will present thereon aliquid-soluble indicator which will respond to the liquid in the plasterwhich has been spread thereover, to effect a bleeding of theliquid-soluble indicator through the plaster to the outer surfacethereof to indicate the position of the receptacle, which is then hiddenunder the coat of plaster. Toward the end of immediately locating thereceptacles hidden under the plastering, a colored substance such as adye is used for bleeding through the plaster.

Thus, a further object of this invention is to provide a servicereceptacle and cover therefor, in combination with a liquid-solublecolored indicator which will cooperate with the liquid in plaster tobleed through the plaster spread thereover, so as to positively locatethe receptacle hidden under the plaster.

Further objects and advantages of this invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize this invention will be pointed out with particularity inthe claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanyingdrawings, in which:

Figure 1 is a fragmentary elevation view of a portion of a plasteredwall having a service receptacle hidden thereunder.

Figure 2 is an enlarged cross-section view taken on line 2-2 of Figure1.

Figure 3 is a front elevation of the apertured face plate of a servicereceptacle that is equipped with one form of this invention.

Figure 4 is a perspective view of the cover plate shown in Figure 3.

Figure 5 is a perspective view of a modified form of cover plate.

Referring now to the drawings, there is shown in Figures 1 and 2 asegment of a wall 10 constructed in part of plaster and within which aservice receptacle generally indicated at 12 is positioned. The mannerof mounting the receptacle 12 within the wall is not shown, but it willbe understood that the receptacle may be mounted either on thestructural studding within the wall or on a tubular conduit whichprojects from a support within the wall.

As is well known in the art, the receptacle 12 includes a preformed box14 which may be provided with a plurality of knock-out portions 16. Aface plate, generally indicated at 18, is arranged to be mounted on theouter open side of the box 14, and includes a mounting flange 20 withinwhich a plurality of slotted holes 21 are provided, which affordsconnection of the face plate 18 to mounting flanges (not shown) on thebox 14. A typical construction of the face plate 18 is illustrated inthe accompanying drawings and includes a dished portion which extendsoutwardly relative to the mounting flange 2t) and which provides anannular side wall 22, and an outermost side 23 within which is formed arelatively large rectangular aperture 24.

The outermost side 23 of the face plate 18 provides, in elfect, a pairof flanges having tapped holes 26 therein and to which a switch body maybe connected in a manner that is well known in the art. The aperture 24accommodates entrance of the switch body into the receptacle 12 when theswitch body is appropriately mounted and connected to the receptacle 12through the tapped holes 26. Thus far, what has been described isconstruction of a type that is standard in the art.

When the receptacle 12 is mounted in the wall 10, as is best seen inFigure 2, portions of the receptacle are embedded in a substantiallythick layer of wall plaster 28, and a relatively thinner layer offinishing plaster 30 is generally provided which normally covers theouter most side 23 of the face plate 18. Of course, during theplastering operation, if the aperture 24 in the face plate 18 isuncovered, plaster would enter the receptacle 12, and the receptaclewould later have to be cleaned out when the electrician completes hisinstallation.

Now, in the instant invention, there is provided a cover plate,generally indicated at 32, which is of a general shape and conformationcorresponding with the shape and conformation of the aperture 24, sothat when the over plate 32 is mounted on the face plate 18, said coverplate occupies, and thereby covers, substantially the entire opening 24in the outer side of the receptacle, so as to prevent plaster fromentering the receptacle when the plaster is spread over the portion ofthe wall in which the receptacle 12 is mounted. In order to releasablymaintain the cover plate 32 in position on the face plate 18, the coverplate 32 is preformed to provide a plurality of mounting tabs 34 whichare generally rearwardly bent so as to project through the aperture 24and to engage portions of the inner surface of side 23. The cover plate32 is formed of a somewhat flexible construc tion, such as of thin metalor the like, so that the mounting tabs 34 may be press-fit through theaperture 24, and the resiliency of the plate 32 and tabs 34 will causethe tabs to spread outwardly thereafter to engage the inner surface ofside 23 to releasably maintain plate 32 on face plate 18.

The cover plate 32 is also provided with a pair of outwardly extendingcover tabs 36 which are adapted to engage the outer surface of the side23 and to cooperate with the mounting tabs 34 to maintain the coverplate 32 properly in position on the face plate 18, and the cover tabs36 serve the additional function of overlying and protecting the tappedholes 26, so as to prevent Wet plaster from entering the tapped holesduring the plastering operation. The greater portion of cover plate 32is disposed in edgewise alignment with the edges of side 23 surroundingaperture 24 and operates to restrain lateral movement of plate 32.

The cover plate 32 not only serves the function of preventing plasterfrom entering receptacle 12, but also serves as an indicator supportmeans in a manner as now described. There is positioned centrally of thecover plate 32 a liquid-soluble indicator means which is adapted torespond to, and cooperate with, the liquid in the wet plaster that isspread thereover, so that the liquid-soluble indicator will bleedthrough the plaster to the outer surface thereof to indicate theposition of the indicating means under the plaster finish coat 30. Morespecifically, the plate 32 is provided with a depression 38 centrallythereof, and positioned within the depression 38 is an indicatorcontaining body 40, which is adapted to be contacted by the plasterspread thereover. The body 40 carries or contains a dye constituting acolored, liquid-soluble substance, and the body 40 also includes acarrier which is operative to inhibit instant bleeding of theliquid-soluble substance into the Wet plaster as the plaster is spreadthereover. The carrier for the dye is further designed to be operativeto permit gradual re lease of the colored liquid-soluble substance intothe wet plaster spread thereover.

In one form of the indicating means here disclosed, which indicatingmeans 40 includes the carrier. for the dye and the dye carried thereby,there is utilized, as the carrier, a gelatin of the type that is usedin. hectographtype duplicators. To form the combination or mixture ofcarrier and dye carried thereby, the hectograph gelatin may be heated upto a liquid stage and may be mixed or impregnated with a suitable amountof liquid dye. After cooling, the gelatin firms up, and there exists anappropriate body of carrier with dye therein, which serves as the body40. The body 40 is retained in depression 38 on plate 32 in any.appropriate manner, such .4 as by the gelatin adhering to the plate 32.The gelatin in body 40 does not go into immediate solution with the wetplaster that is spread thereover and, hence, it operates to inhibit theimmediate release of the dye as the wet plaster contacts the gelatinbody 40. However, the gelatin does react slowly with the liquid in theplaster so that there is a gradual release of the colored dye into thewet plaster. After the plaster has dried, the dye will have bled throughthe plaster finish coat 30, and is immediately visible to theelectrician who is searching for the receptacle.

An alternate form of carrier for body 40 may consist of a wad of cottonor other dye-absorbing and carrying material. Again, the cotton with dyecarried thereby operates to inhibit immediate release of the entireamount of dye carried by the mass 40 but, upon contact with the wetplaster over a period of time, there is a gradual leaking of the dyeinto the plaster, so that the dye will bleed to the outer surface of theplaster finish coat 30.

Hectograph gelatin, which has been used to make body 40, is understoodto be gelatin tanned with dichromate. It is important that the dyeswhich are used be water-soluble, and may be of almost any color, asdesired. One dye that has been successfully used is Du Pont CroceinScarlet N, and there are many families of such Water-soluble dyes whichcould be used, including naphthol sulphonic acid dyes, such as Du PontCrocein Scarlet N, triphenylmethanes, such as brilliant blue FCF orGuinea Green B, and monoazos, such as Orange I or Ponceau 3R.

In the alternate construction shown in Figure 5, the cover plate 32 isprovided with a central aperture 50. A body of dye-releasing indicatingmaterial 52 is mounted on a pressure-sensitive tape segment 54 which maybe adhered to the inner surface of the cover plate 32', so that theliquid-soluble dye-releasing body 52 protrudes through aperture 50, andso that the wet plaster which is spread over the cover plate 32' willengage the body 52 which contains the liquid-soluble substance.

After the electrician has located a hidden receptacle 12 by observingthe place where the dye has seeped through the plaster finish coat 30,the electrician may chip away the plaster covering the face plate 32 andthen remove the plate 32, or may alternatively push inwardly against theplaster coat 30 substantially centrally of the cover plate 32, therebyetfecting a deforma tion of cover plate 32 into the folded positionshown in dot-dash lines in Figure 2. The deformed cover plate 32 may bethen withdrawn from the receptacle 12 and discarded, leaving thereceptacle 12 in condition to receive a switch body for which it isprovided.

Alternatively, in the use of the device in Figure 5 the existence of theaperture 50 permits the electrician to push a tool through, the aperture50 thereby rupturing or displacing tape 54, to permit him to engage theinner surface of cover plate 32' and then, by pulling outwardly, thecover plate 32' is removed from the receptacle 12, thereby leaving thereceptacle 12 in proper condition to regeilve the switch body for whichthe receptacle is pro- -v1 e As best shown in Figure 2, the indicatorcontaining body 40 is preferably flush with the outer side of coverplate 32, or may alternatively protrude just slightly outwardly of plate32 so as to insure that the body 40 will contact the plaster coat 3!)spread thereover. It is important that the indicatorcontaining body 40notsmear when the plaster is spread thereover, and it is important thatthe body 40 be positioned where the wet plaster will engage it so thatthe indicator will bleed through the plaster coat 3Q as is indicated bythe dotted type shading seen in Figure 2 It will also be understood thatplates 32 or 32' carrying an indicator containing body 40 or 52 may be.provided with removable coversheets for protecting the body 40 or 52until itis desired to use. the device as hereinabovedescribed.

While there has been shown and described a particular embodiment of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made therein without departing from theinvention and, therefore, it is intended in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is:

1. A position indicating device for use with a service receptacle thatis positioned within plastered walls; said indicating device comprising,in combination, indicator support means positioned adjacent said servicereceptacle and presenting an outer face over which wet plaster isadapted to be spread when the wall is plastered, and an indicatorcarried on said indicator support means and having its outermost portionpositioned substantially in the plane of the outer face of saidindicator support means and operating to indicate the position of theindicating device on the outer surface of the plaster after the plasterhas been spread thereover.

2. A position indicating device for use with a service receptacle thatis positioned within plastered walls; said indicating device comprising,in combination, indicator support means positioned adjacent said servicereceptacle and presenting an outer face over which wet plaster isadapted to be spread when the wall is plastered, and a liquid-solubleindicator carried by said indicator support means and having itsoutermost portion positioned substantially in the plane of said outerface of said support means and positioned to be engaged by the wetplaster spread thereover.

3. A position indicating device for use with a service receptacle thatis positioned within plastered walls; said indicating device comprising,in combination, indicator support means positioned adjacent said servicereceptacle and presenting an outer face over which wet plaster isadapted to be spread when the wall is plastered, and a liquid-solubleindicator carried by said indicator support means and having itsoutermost portion positioned sub stantially in the plane of said outerface of said support means and positioned to be engaged by the wetplaster spread thereover; and said liquid-soluble indicator respondingto the liquid in said wet plaster to bleed through the plaster to theouter surface thereof to visually indicate the position of theindicating device after plaster has been spread thereover.

4. A position indicating device for use with a service receptacle thatis positioned within plastered walls; said indicating device comprising,in combination, indicator support means positioned adjacent said servicereceptacle and presenting an outer face over which wet plaster isadapted to be spread when the wall is plastered, a liquidsolubleindicator carried by said indicator support means and having itsoutermost portion positioned substantially in the plane of said outerface of said support means and positioned to be engaged by the wetplaster spread thereover, said liquid-soluble indicator responding tothe liquid in said wet plaster to bleed through the plaster to the outersurface thereof to visually indicate the position of the indicatingdevice after plaster has been spread thereover, and said liquid-solubleindicator comprising a carrier impregnated with a colored liquid-solublesubstance, said carrier being operative to permit gradual release of thecolored liquid-soluble substance into the wet plaster spread thereover.

5. A position indicating device for use with a service receptacle thatis positioned within plastered walls; said indicating device comprising,in combination, indicator support means positioned adjacent said servicereceptacle and presenting an outer face over which wet plaster isadapted to be spread when the wall is plastered, a liquidsolubleindicator carried by said indicator support means and having itsoutermost portion positioned substantially in the plane of said outerface of said support means and 6, positioned to be engaged by the wetplaster spread there over, and said liquid-soluble indicator respondingto the liquid in said wet plaster to bleed through the plaster to theouter surface thereof to indicate the position of the indicating deviceafter plaster has been spread thereover, said liquid-soluble indicatorcomprising a carrier containing a colored liquid-soluble substance, saidcarrier being operative to inhibit instant bleeding of the coloredliquid-soluble substance into the wet plaster spread thereover, and saidcarrier being operative to permit gradual release of the coloredliquid-soluble substance into the wet plaster spread thereover.

6. A device as set forth in claim 2 wherein said liquidsoluble indicatorcomprises a dye.

7. A device as set forth in claim 5 wherein said liquidsoluble indicatorcomprises an insoluble absorbent carrier carrying a coloredliquid-soluble substance.

8. A device as set forth in claim 5 wherein said liquidsolulbleindicator comprises a liquid-soluble carrier mixed with a coloredliquid-soluble substance.

9, A device as set forth in claim 5 wherein said liquidsoluble indicatorcomprises a liquid-soluble carrier mixed with a colored liquid-solublesubstance, and said carrier being a gelatin.

10. A device as set forth in claim 1 wherein the said service receptaclehas an outwardly facing apertured side, and wherein said indicatorsupport means is a cover plate which substantially covers the entireopening in said apertured side of the receptacle to prevent plaster fromentering the receptacle when Wet plaster is spread thereover, and saidcover plate having a mounting means formed centrally thereof whereatsaid indicator is positioned.

11. A device as set forth in claim 2 wherein the said service receptaclehas an outwardly facing apertured side, and wherein said indicatorsupport means is a cover plate which substantially covers the entireopening in said apertured side of the receptacle to prevent plaster fromentering the receptacle when wet plaster is spread thereover, and saidcover plate having a central depression wherein said liquid-solubleindicator is positioned.

12. A device as set forth in claim 1 wherein the said service receptaclehas an outwardly facing apertured side, and wherein said indicatorsupport means is a single cover plate which substantially covers theentire opening in said apertured side of the receptacle to preventplaster from entering the receptacle when wet plaster is spreadthereover, and said cover plate having releasable mounting means formedfrom the material of said cover plate and engaging opposite surfaces ofthe apertured side of the receptacle.

13. A device as set forth in claim 1 wherein the said service receptaclehas an outwardly facing apertured side, and wherein said indicatorsupport means is a cover plate which substantially covers the entireopening in said apertured side of the receptacle to prevent plaster fromentering the receptacle when wet plaster is spread thereover, and saidcover plate having a centrally located aperture through which a tool maybe introduced to effect engagement between the tool and the cover plateto afford removing the cover plate with the said tool.

14. A shield for use with a service receptacle that is positioned withinplastered walls, wherein said service receptacle has an outwardly facingapertured side provided with tapped attachment flanges thereon; saidshield comprising a single cover plate that is releasably mounted onsaid receptacle and substantially covers the entire opening in saidapertured side of the receptacle to prevent plaster from entering thereceptacle when wet plaster is spread thereover, said cover plate havingreleasable mounting means including resilient mounting tabs integralwith said cover plate on opposite edges of said cover plate and whichmay be press-fit through the aperture in said receptacle to engage theinside of the receptacle adjacent the edges of said aperture, and saidcover plate References Cited in the file of this patent UNITED STATESPATENTS Fieberl i'ng iune 11, 1935

